High-resolution and miniaturized spectrometers without moving parts have a great potential for use in optical fiber communication networks, environmental sensing, and medical diagnostics. Spatial heterodyne spectroscopy (SHS) is an interferometric technique that uses the Fourier transformation of the stationary interference pattern from Mach-Zehnder interferometers (MZIs). The planar waveguide version of the SHS architecture is one of the key solutions, since the MZI array can be fabricated on one substrate.
The actual optical delays of the fabricated MZIs are likely to deviate from their designed values and the phase error frozen in each MZI may prevent one from producing the correct spectrum.
This invention addresses the problem of assessing the potential errors in the spectrum produced by such spectrometers.